Habitat destruction by human activity and the consequent extinction of species around the world could turn parasites into “evolutionary land mines”, warned a Canadian zoologist speaking at the annual meeting of the American Association for the Advancement of Science. Dr. Daniel Brooks, a parasitologist at the University of Toronto, says the decline of global biodiversity is linked to the emergence of new human and wildlife diseases such as West Nile Virus and avian flu.
“The biodiversity crisis is not just about extinctions,” says Brooks. “In the past, when there have been episodes of major climate change or mass extinction, and species have moved out of their areas of origin into other areas, there have been emerging diseases. Parasites have moved into new areas and they’ve jumped ship into new hosts.” Brooks has spent much of the past decade in the dense jungles of Costa Rica tracking down and collecting parasites. Since 1996, he has coordinated the parasite Taxonomic Working Group for the All-Taxa Biodiversity Inventory, an international scientific and economic initiative to help developing countries preserve the world’s biodiversity.
“Right now, we’re just reacting out of ignorance whenever an unfamiliar disease catches us off guard and we call that management,” said Brooks. “We’re always behind the curve, because we don’t know where these things are coming from.”
In fact, while parasites like malaria are well known, we may have identified only a fraction of the total number of the world’s parasites, and the prospect of cataloguing them poses a daunting technical challenge. Since the physical characteristics of many parasites are very similar, Brooks and his colleagues are using the latest molecular taxonomy tools to classify parasites based on genetic characteristics. “These things are evolutionary accidents waiting to happen,” he warned. “These little evolutionary land mines are going to jump up and bite us.”